ESTRO 2021 Abstract Book

S1134

ESTRO 2021

Results With a median follow-up of 15.5 months (range 3-65 months), 16 patients (62%) are alive without tumor while 10 (38%) are alive with tumor. Four patients (17%) developed tumor progression, out of irradiated area in all cases, with a median time to progression of 43.5 months (range 27-56 months). Actuarial progression-free survival (PFS) rates at 12 and 24 months were 94.1% and 84.7%, respectively Fig.2). No grade >2 acute or late complications were recorded. Fig.2: Kaplan-Meier curve for progression-free survival (PFS)

Conclusion Simultaneous directed radical hypofractionated radiation therapy for prostate and metastases is feasible, well tolerated and achieves acceptable PFS rate in de novo oligometastatic prostate carcinoma. Further studies with longer follow-up are necessary to definitively address this observations. PO-1384 Salvage radiotherapy for locally recurrent prostate cancer after high-intensity focused ultrasound N. Jullian 1 , R. Diamand 2 , A. Mattlet 2 , S. Poeta 3 , K. Limani 2 , A. Peltier 2 , D. Van Gestel 1 , F. Otte 1 1 Institut Jules Bordet - Université Libre de Bruxelles, Radiation Oncology, Bruxelles, Belgium; 2 Institut Jules Bordet - Université Libre de Bruxelles, Urology, Bruxelles, Belgium; 3 Institut Jules Bordet-Université Libre de Bruxelles, Medical Physics, Bruxelles, Belgium Purpose or Objective The aim of this study is to evaluate the oncological outcome and side effects of radiotherapy as salvage treatment for locally recurrent prostate cancer (PCa) after high-intensity focused ultrasound (HIFU) for the primary tumour. Materials and Methods We retrospectively analyzed 79 patients treated in our institution between 2016 and 2020 by Focal One® HIFU (Edap TMS, France) as primary treatment for localized prostate cancer detected on systematic and MRI- targeted biopsy. Basic follow-up consisted of serial PSA tests and digital rectal examinations every three months. In case of positivity, local relapse was confirmed by clinically significant follow-up biopsy (ISUP grade group ≥2) or by a 68 Ga-Prostate-specific membrane antigen (PSMA) PET-CT positive lesion within the prostate.